The earliest papers, 1828-1843, cover the years when Cornell worked in Ithaca and travelled for Barnaby and Mooers plows. They include letters, accounts, and other papers concerning his employment by Jeremiah Beebe, the owner of a flour and plaster mill on Fall Creek in Ithaca, N.Y. and his other business interests in Ithaca. Family letters contain information about his work, plans and opinions; news about his growing family; and reports of events in Ithaca. After 1838, there is considerable detail about Cornell's travels in Maine and Georgia, selling Barnaby and Mooers plows.

Papers, 1843-1860, relate to the promotion, construction, and investment in telegraph lines in the eastern and midwestern United States and Canada, and include contracts, lists of stockholders, briefs of legal cases, accounts, financial statements and reports, broadsides, pamphlets, and sketches; a series of letters from Samuel F.B. Morse; material relating to the construction of the first telegraph line from Washington to Baltimore; and material relating to Cornell's construction and operation of other lines. The papers reveal the difficulties of construction and maintenance, and the conflicts between investors. Of particular interest is the material dealing with the beginnings of Western Union (1854-1855).

There are also papers relating to Cornell's agricultural interest in purebred stock and in the Tompkins County and New York State Agricultural Societies; his interest in coal lands and coal oil in Pennsylvania; his building of the Cornell Library in Ithaca; his interest in the Casacadilla health resort; and to his promotion of the growth of Ithaca.

After 1860 the papers relate to local, state, and national politics; his election to the New York State Legislature; the Albany Agricultural Works; the development of railway lines including the Utica, Ithaca, and Elmira Rail Road, the Geneva & Ithaca Rail Road, the Ithaca & Cortland Railroad, and the Erie Railroad; correspondence with and relief efforts for Civil War soldiers.

Correspondence, drawings and maps, and other papers pertaining to the conception, founding, and construction of Cornell University, with particular reference to Andrew Dickson White, the first President.

Diary/memo books include information ranging from the weight of cattle to genealogical tables, personal accounts, and notes on western lands, as well as his legislative career and the founding of the university.

Includes glazed pitcher and two large pots crafted by Elijah Cornell, father of Ezra Cornell.

Major correspondents include Mary Ann Cornell, Alonzo B. Cornell, Daniel B. Cornell, Samuel F.B. Morse, Jeremiah Beebe, J.J. Speed, D.T. Tillotson, Amos Kendall, F.O.J Smith, Andrew Dickson White, Hiram Sibley, F.M. Finch, and Phebe Wood.

Accounts, broadsides, correspondence, estimates, memoranda, maps, newspaper clippings, and other papers.